Apparatus for monitoring an item for radioactive material on or associated with the item

Abstract

Method and apparatus is provided for monitoring an item for radioactive material on or associated with the item, the apparatus including an enclosed volume, an item monitoring location, a detection location, ion detectors provided within the detection location, a mover of gas for providing a flow of gas past the item monitoring location to a detection location, so as to revel the level and/or presence of radioactive material on the item. The item may be supported within the monitoring location by one or more rollers to ease its insertion and/or removal. The item monitoring location may be extremely elongate so as to measure pipes and the like. Various designs of roller and gas flow controllers are provided to optimize monitoring.

1. Apparatus for monitoring an item for radioactive material on or associated with the item, the apparatus comprising an enclosed volume, the enclosed volume including an item monitoring location and a detection location, the detection location including ion detectors, a mover of gas for providing a flow of gas past the item monitoring location to the detection location, wherein an item support system is provided at the item monitoring location, the item support system including one or more rollers. 
     
     
       2. Apparatus for monitoring an item for radioactive material on or associated with the item preferably according to  claim 1 , wherein the enclosed volume has a length extending from one end to the other, the length is considered perpendicular to a width, the length is at least 5 times the width, the item is introduced to the item monitoring location through a closeable opening and the closeable opening is provided at one end of the enclosed volume. 
     
     
       3. Apparatus according to  claim 1  in which the item is moved to the monitoring location along its longest axis. 
     
     
       4. Apparatus according to  claim 1  in which the middle of the support system components is lower than the ends of the support system component. 
     
     
       5. Apparatus according to  claim 4  in which two rollers whose adjoining ends are lower than their distal ends are provided. 
     
     
       6. Apparatus according to  claim 1  in which one or more of the rollers is powered. 
     
     
       7. Apparatus according to  claim 1  in which the closeable opening is included in the end wall of the enclosed volume. 
     
     
       8. Apparatus according to  claim 1  in which the closeable opening is included in at least part of the side wall of the enclosed volume. 
     
     
       9. Apparatus according to  claim 1  in which one or more gas flow controllers are provided between a gas entrance to the enclosed volume and the item monitoring location. 
     
     
       10. Apparatus according to  claim 9  in which a gas flow controller in the form of one or more parallel planar elements is provided, the gas flow controllers being aligned with the long axis of the apparatus. 
     
     
       11. Apparatus according to  claim 9  in which a plurality of gas flow controllers are provided in one orientation and another plurality are provided in another orientation, the orientations being perpendicular to one another. 
     
     
       12. Apparatus according to  claim 9  in which the gas flow controllers are in the form of hollow elements, such as tubes. 
     
     
       13. Apparatus according to  claim 9  in which a gas flow controller is provided, the gas flow controller extending radially inward from the wall or walls defining the enclosed volume, an aperture being provided in the gas flow controller, the axis of the aperture being aligned with the axis of the item. 
     
     
       14. Apparatus according to  claim 9  in which the one or more gas flow controllers determine the proportion of the gas flow which passes around the outside of a hollow item and/or through the item. 
     
     
       15. Apparatus according to  claim 9  in which a gas flow controller is provided, the gas flow controller being in a form which has a first portion substantially aligned with the direction of gas flow through the inlet to the enclosed volume and a second portion substantially aligned with the axis of the enclosed volume and/or its length and/or the direction of gas flow through the enclosed volume. 
     
     
       16. Apparatus according to  claim 15  in which the first portion and second portion are joined by a transition portion which changes alignment from one to the other. 
     
     
       17. Apparatus according to  claim 1  in which one or more gas flow controllers are provided within the item monitoring location, the gas flow controllers being part of the support system for the item. 
     
     
       18. Apparatus according to  claim 17  in which the gas flow controllers are in the form of one or more circular elements, such as discs, the elements or discs having a radial extent about an axis which is even in all directions in that plane, the axis being the axis of rotation of the roller. 
     
     
       19. A method of monitoring an item for radioactive material on or associated with the item, the method comprising: providing an enclosed volume, introducing an item through a closeable opening in one end of the chamber to provide the item at an item monitoring location; moving gas in the enclosed volume past the item monitoring location to a detection location; detecting ions in the gas using the detectors at the detecting location; wherein the item is moved to the item monitoring location on a support system including one or more rollers, the detection for ions in the medium is performed whilst the item is on the same support system. 
     
     
       20. A method of monitoring an item for radioactive material on or associated with the item according to  claim 19 , the method comprising:
 providing an enclosed volume, the enclosed volume having a length extending from one end to the other, the length being considered perpendicular to a width, the length being at least 5 times the width; 
 introducing the item to the item monitoring location through a closeable opening provided at one end of the enclosed volume; 
 moving gas in the enclosed volume past the item monitoring location to a detection location; 
 detecting ions in the gas using the detectors at the detecting location. 
 
     
     
       21. A method according to  claim 19  in which the item is an elongate item, such as a pipe, rail, I-beam or the like. 
     
     
       22. A method according to  claim 19  in which the same item is subjected to at least two detections, between one detection and another the position of the item within the item monitoring location being changed. 
     
     
       23. A method according to  claim 22  in which the change is provided by moving the item along the path travelled to move it to the item monitoring location. 
     
     
       24. A method according to  claim 22  in which the change is provided by rotating the item, ideally about its axis. 
     
     
       25. A method according to  claim 19  in which the gas flow within the enclosed volume is controller using one or more gas flow controllers. 
     
     
       26. A method according to  claim 19  in which the enclosed volume is formed by joining a plurality of sections together, the sections including a first section having a gas inlet to the enclosed volume and a second section having a gas outlet from the enclosed volume and one or more optional third sections for linking the first section to the second section. 
     
     
       27. A method according to  claim 19  in which gas flows from the outlet to the inlet along a return passage, the gas passing through the detection location and/or mover of gas and/or an ion filter during its flow along the return passage.